The present invention relates to doors or windows which are moved along horizontal tracks and more particularly to improved sliding track members.
Sliding doors which are supported mainly by overhead tracks were disclosed by Hermanson, U.S. Pat. No. 4,344,206. Hermanson recognized the need to have the tracks be alignable not only laterally but also longitudinally.
Vater, U.S. Pat. No. 4,457,046, like Hermanson, also taught the use of an overhead track for a sliding door panel or the like. To reduce friction between his track and the panel, Vater utilized an assembly of rollers with needle roller bearings to form a roller carriage assembly.
Shelton, U.S. Pat. No. 4,483,045, introduced a track having a rounded bottom along which a ball shaped roller moves. Shelton's ball-shaped roller is so mounted as to allow the door to be self-centering in the track.
The tracks and guides for sliding door in the prior art are mounted over the doors. Other means for restraining the doors is required to secure them along their lower edges. Furthermore, the prior art teaches the use of bearings to overcome friction forces generated while sliding the doors along their tracks.